Increasing entropy in VM
Access to high-quality random numbers is important for the proper functioning of an operating system, in particular for its security related components and applications. In case the rate by which /dev/random provides random numbers within a VM is not sufficient, users can install the rngd service to generate random numbers from the underlying processor's Digital Random Number Generator (DRNG):
RedHat - CentOS
$ yum install -y rng-tools $ systemctl start rngd
Debian - Ubuntu
$ apt install -y rng-tools $ systemctl start rngd
This will increase the rate at which random numbers are available from /dev/random, but avoid the lower-quality pseudo-random numbers from /dev/urandom.